This invention relates generally to a track system for a work machine and, more particularly, to an apparatus and method for measuring and realigning track misalignment during operation.
Some present day endless track laying work machines utilize a track that is an endless rubber belt as the means for propulsion. The endless rubber belt is tensioned into frictional engagement with and entrained about a drive wheel and an idler wheel. Problems encountered in reducing such an endless track laying work machine to practice include how to maintain adequate tension on such belt and laterally aligning the belt to run true with the drive and idler wheels. Other problems are maintaining the structural integrity and providing long life of the belt and other associated drive train components.
Examples of prior belt alignment mechanism are shown in U.S. Pat. Nos. 5,127,714 and 5,312,176. In both examples the alignment of the track is adjusted by moving an arm that is pivotally attached to the idler wheel. Movement of the arm is accomplished through a jack screw arrangement with a jam nut used to lock the arm in place. Both patents provide a manual means for adjusting the alignment of the idler wheel to keep the belt in proper alignment and entrained around the drive and idler wheels during assembly or a maintenance procedure. However, neither patent provides an apparatus or method for measuring misalignment during operation of the endless track laying work machine at the time of initial startup or as components wear or loosen and then realigning thereafter.
The present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the current invention an apparatus for measuring misalignment and realigning a track on a work machine is provided. The work machine utilizes a pair of track roller assemblies each having a track entrained around a drive wheel and an idler wheel. The idler wheel has first and second wheel segments one each being rotatably positioned on opposite sides of a plurality of guide elements. The guide elements are positioned on an inner surface of the track. The apparatus has a sensor positioned adjacent the first and second wheel segments and a controller in communication with the at least one sensor.
In another aspect of the current invention a method is provided for aligning a track of a work machine. The work machine utilizes a pair of track roller assemblies each having a track entrained around a drive wheel and an idler wheel. The idler wheel has first and second wheel segments rotatably positioned on opposite sides of a plurality of guide elements. The plurality of guide elements are positioned on an inner surface of the track. The method comprises the steps of sensing a parameter indicative of the contact between the first wheel segment and the plurality of guide elements, and responsively delivering a first signal. Sensing a parameter indicative of the contact between the second wheel segment and the plurality of guide elements, and responsively delivering a second signal. Delivering a differential range signal indicative of a desired contact differential between one of the first and second wheel segments and the first and second sides of the plurality of guide elements. Determining an actual contact differential based on a comparison of the first signal and the second signal. Comparing the actual differential and the desired differential range. And pivoting the idler wheel responsive to the higher of the first and second signals until the actual differential falls within the desired differential range.